<?php
/**
 * A helper class for fixing errors.
 *
 * Provides helper functions that act upon a token array and modify the file
 * content.
 *
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @copyright 2006-2015 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   https://github.com/squizlabs/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
 */

namespace PHP_CodeSniffer;

use PHP_CodeSniffer\Files\File;
use PHP_CodeSniffer\Util\Common;

class Fixer
{
    /**
     * Is the fixer enabled and fixing a file?
     *
     * Sniffs should check this value to ensure they are not
     * doing extra processing to prepare for a fix when fixing is
     * not required.
     *
     * @var bool
     */
    public $enabled = false;

    /**
     * The number of times we have looped over a file.
     *
     * @var int
     */
    public $loops = 0;

    /**
     * The file being fixed.
     *
     * @var \PHP_CodeSniffer\Files\File
     */
    private $currentFile;

    /**
     * The list of tokens that make up the file contents.
     *
     * This is a simplified list which just contains the token content and nothing
     * else. This is the array that is updated as fixes are made, not the file's
     * token array. Imploding this array will give you the file content back.
     *
     * @var array<int, string>
     */
    private $tokens = [];

    /**
     * A list of tokens that have already been fixed.
     *
     * We don't allow the same token to be fixed more than once each time
     * through a file as this can easily cause conflicts between sniffs.
     *
     * @var int[]
     */
    private $fixedTokens = [];

    /**
     * The last value of each fixed token.
     *
     * If a token is being "fixed" back to its last value, the fix is
     * probably conflicting with another.
     *
     * @var array<int, string>
     */
    private $oldTokenValues = [];

    /**
     * A list of tokens that have been fixed during a changeset.
     *
     * All changes in changeset must be able to be applied, or else
     * the entire changeset is rejected.
     *
     * @var array
     */
    private $changeset = [];

    /**
     * Is there an open changeset.
     *
     * @var bool
     */
    private $inChangeset = false;

    /**
     * Is the current fixing loop in conflict?
     *
     * @var bool
     */
    private $inConflict = false;

    /**
     * The number of fixes that have been performed.
     *
     * @var int
     */
    private $numFixes = 0;

    /**
     * Starts fixing a new file.
     *
     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file being fixed.
     */
    public function startFile(File $phpcsFile)
    {
        $this->currentFile = $phpcsFile;
        $this->numFixes = 0;
        $this->fixedTokens = [];

        $tokens = $phpcsFile->getTokens();
        $this->tokens = [];
        foreach ($tokens as $index => $token) {
            if (true === isset($token['orig_content'])) {
                $this->tokens[$index] = $token['orig_content'];
            } else {
                $this->tokens[$index] = $token['content'];
            }
        }
    }

    //end startFile()

    /**
     * Attempt to fix the file by processing it until no fixes are made.
     *
     * @return bool
     */
    public function fixFile()
    {
        $fixable = $this->currentFile->getFixableCount();
        if (0 === $fixable) {
            // Nothing to fix.
            return false;
        }

        $this->enabled = true;

        $this->loops = 0;
        while ($this->loops < 50) {
            ob_start();

            // Only needed once file content has changed.
            $contents = $this->getContents();

            if (PHP_CODESNIFFER_VERBOSITY > 2) {
                @ob_end_clean();
                echo '---START FILE CONTENT---' . PHP_EOL;
                $lines = explode($this->currentFile->eolChar, $contents);
                $max = \strlen(\count($lines));
                foreach ($lines as $lineNum => $line) {
                    ++$lineNum;
                    echo str_pad($lineNum, $max, ' ', STR_PAD_LEFT) . '|' . $line . PHP_EOL;
                }

                echo '--- END FILE CONTENT ---' . PHP_EOL;
                ob_start();
            }

            $this->inConflict = false;
            $this->currentFile->ruleset->populateTokenListeners();
            $this->currentFile->setContent($contents);
            $this->currentFile->process();
            ob_end_clean();

            ++$this->loops;

            if (PHP_CODESNIFFER_CBF === true && PHP_CODESNIFFER_VERBOSITY > 0) {
                echo "\r" . str_repeat(' ', 80) . "\r";
                echo "\t=> Fixing file: {$this->numFixes}/{$fixable} violations remaining [made {$this->loops} pass";
                if ($this->loops > 1) {
                    echo 'es';
                }

                echo ']... ';
            }

            if (0 === $this->numFixes && false === $this->inConflict) {
                // Nothing left to do.
                break;
            }
            if (PHP_CODESNIFFER_VERBOSITY > 1) {
                echo "\t* fixed {$this->numFixes} violations, starting loop " . ($this->loops + 1) . ' *' . PHP_EOL;
            }
        }//end while

        $this->enabled = false;

        if ($this->numFixes > 0) {
            if (PHP_CODESNIFFER_VERBOSITY > 1) {
                if (ob_get_level() > 0) {
                    ob_end_clean();
                }

                echo "\t*** Reached maximum number of loops with {$this->numFixes} violations left unfixed ***" . PHP_EOL;
                ob_start();
            }

            return false;
        }

        return true;
    }

    //end fixFile()

    /**
     * Generates a text diff of the original file and the new content.
     *
     * @param string $filePath Optional file path to diff the file against.
     *                         If not specified, the original version of the
     *                         file will be used.
     * @param bool   $colors   Print coloured output or not.
     *
     * @return string
     */
    public function generateDiff($filePath = null, $colors = true)
    {
        if (null === $filePath) {
            $filePath = $this->currentFile->getFilename();
        }

        $cwd = getcwd() . \DIRECTORY_SEPARATOR;
        if (0 === strpos($filePath, $cwd)) {
            $filename = substr($filePath, \strlen($cwd));
        } else {
            $filename = $filePath;
        }

        $contents = $this->getContents();

        $tempName = tempnam(sys_get_temp_dir(), 'phpcs-fixer');
        $fixedFile = fopen($tempName, 'w');
        fwrite($fixedFile, $contents);

        // We must use something like shell_exec() because whitespace at the end
        // of lines is critical to diff files.
        $filename = escapeshellarg($filename);
        $cmd = "diff -u -L{$filename} -LPHP_CodeSniffer {$filename} \"{$tempName}\"";

        $diff = shell_exec($cmd);

        fclose($fixedFile);
        if (true === is_file($tempName)) {
            unlink($tempName);
        }

        if (false === $colors) {
            return $diff;
        }

        $diffLines = explode(PHP_EOL, $diff);
        if (1 === \count($diffLines)) {
            // Seems to be required for cygwin.
            $diffLines = explode("\n", $diff);
        }

        $diff = [];
        foreach ($diffLines as $line) {
            if (true === isset($line[0])) {
                switch ($line[0]) {
                case '-':
                    $diff[] = "\033[31m{$line}\033[0m";

                    break;
                case '+':
                    $diff[] = "\033[32m{$line}\033[0m";

                    break;
                default:
                    $diff[] = $line;
                }
            }
        }

        return implode(PHP_EOL, $diff);
    }

    //end generateDiff()

    /**
     * Get a count of fixes that have been performed on the file.
     *
     * This value is reset every time a new file is started, or an existing
     * file is restarted.
     *
     * @return int
     */
    public function getFixCount()
    {
        return $this->numFixes;
    }

    //end getFixCount()

    /**
     * Get the current content of the file, as a string.
     *
     * @return string
     */
    public function getContents()
    {
        return implode('', $this->tokens);
    }

    //end getContents()

    /**
     * Get the current fixed content of a token.
     *
     * This function takes changesets into account so should be used
     * instead of directly accessing the token array.
     *
     * @param int $stackPtr The position of the token in the token stack.
     *
     * @return string
     */
    public function getTokenContent($stackPtr)
    {
        if (true === $this->inChangeset
            && true === isset($this->changeset[$stackPtr])
        ) {
            return $this->changeset[$stackPtr];
        }

        return $this->tokens[$stackPtr];
    }

    //end getTokenContent()

    /**
     * Start recording actions for a changeset.
     */
    public function beginChangeset()
    {
        if (true === $this->inConflict) {
            return false;
        }

        if (PHP_CODESNIFFER_VERBOSITY > 1) {
            $bt = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
            if (__CLASS__ === $bt[1]['class']) {
                $sniff = 'Fixer';
            } else {
                $sniff = Util\Common::getSniffCode($bt[1]['class']);
            }

            $line = $bt[0]['line'];

            @ob_end_clean();
            echo "\t=> Changeset started by {$sniff}:{$line}" . PHP_EOL;
            ob_start();
        }

        $this->changeset = [];
        $this->inChangeset = true;
    }

    //end beginChangeset()

    /**
     * Stop recording actions for a changeset, and apply logged changes.
     *
     * @return bool
     */
    public function endChangeset()
    {
        if (true === $this->inConflict) {
            return false;
        }

        $this->inChangeset = false;

        $success = true;
        $applied = [];
        foreach ($this->changeset as $stackPtr => $content) {
            $success = $this->replaceToken($stackPtr, $content);
            if (false === $success) {
                break;
            }
            $applied[] = $stackPtr;
        }

        if (false === $success) {
            // Rolling back all changes.
            foreach ($applied as $stackPtr) {
                $this->revertToken($stackPtr);
            }

            if (PHP_CODESNIFFER_VERBOSITY > 1) {
                @ob_end_clean();
                echo "\t=> Changeset failed to apply" . PHP_EOL;
                ob_start();
            }
        } elseif (PHP_CODESNIFFER_VERBOSITY > 1) {
            $fixes = \count($this->changeset);
            @ob_end_clean();
            echo "\t=> Changeset ended: {$fixes} changes applied" . PHP_EOL;
            ob_start();
        }

        $this->changeset = [];
    }

    //end endChangeset()

    /**
     * Stop recording actions for a changeset, and discard logged changes.
     */
    public function rollbackChangeset()
    {
        $this->inChangeset = false;
        $this->inConflict = false;

        if (false === empty($this->changeset)) {
            if (PHP_CODESNIFFER_VERBOSITY > 1) {
                $bt = debug_backtrace();
                if ('PHP_CodeSniffer\Fixer' === $bt[1]['class']) {
                    $sniff = $bt[2]['class'];
                    $line = $bt[1]['line'];
                } else {
                    $sniff = $bt[1]['class'];
                    $line = $bt[0]['line'];
                }

                $sniff = Util\Common::getSniffCode($sniff);

                $numChanges = \count($this->changeset);

                @ob_end_clean();
                echo "\t\tR: {$sniff}:{$line} rolled back the changeset ({$numChanges} changes)" . PHP_EOL;
                echo "\t=> Changeset rolled back" . PHP_EOL;
                ob_start();
            }

            $this->changeset = [];
        }//end if
    }

    //end rollbackChangeset()

    /**
     * Replace the entire contents of a token.
     *
     * @param int    $stackPtr The position of the token in the token stack.
     * @param string $content  The new content of the token.
     *
     * @return bool If the change was accepted.
     */
    public function replaceToken($stackPtr, $content)
    {
        if (true === $this->inConflict) {
            return false;
        }

        if (false === $this->inChangeset
            && true === isset($this->fixedTokens[$stackPtr])
        ) {
            $indent = "\t";
            if (false === empty($this->changeset)) {
                $indent .= "\t";
            }

            if (PHP_CODESNIFFER_VERBOSITY > 1) {
                @ob_end_clean();
                echo "{$indent}* token {$stackPtr} has already been modified, skipping *" . PHP_EOL;
                ob_start();
            }

            return false;
        }

        if (PHP_CODESNIFFER_VERBOSITY > 1) {
            $bt = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
            if ('PHP_CodeSniffer\Fixer' === $bt[1]['class']) {
                $sniff = $bt[2]['class'];
                $line = $bt[1]['line'];
            } else {
                $sniff = $bt[1]['class'];
                $line = $bt[0]['line'];
            }

            $sniff = Util\Common::getSniffCode($sniff);

            $tokens = $this->currentFile->getTokens();
            $type = $tokens[$stackPtr]['type'];
            $tokenLine = $tokens[$stackPtr]['line'];
            $oldContent = Common::prepareForOutput($this->tokens[$stackPtr]);
            $newContent = Common::prepareForOutput($content);
            if ('' === trim($this->tokens[$stackPtr]) && true === isset($this->tokens[($stackPtr + 1)])) {
                // Add some context for whitespace only changes.
                $append = Common::prepareForOutput($this->tokens[($stackPtr + 1)]);
                $oldContent .= $append;
                $newContent .= $append;
            }
        }//end if

        if (true === $this->inChangeset) {
            $this->changeset[$stackPtr] = $content;

            if (PHP_CODESNIFFER_VERBOSITY > 1) {
                @ob_end_clean();
                echo "\t\tQ: {$sniff}:{$line} replaced token {$stackPtr} ({$type} on line {$tokenLine}) \"{$oldContent}\" => \"{$newContent}\"" . PHP_EOL;
                ob_start();
            }

            return true;
        }

        if (false === isset($this->oldTokenValues[$stackPtr])) {
            $this->oldTokenValues[$stackPtr] = [
                'curr' => $content,
                'prev' => $this->tokens[$stackPtr],
                'loop' => $this->loops,
            ];
        } else {
            if ($this->oldTokenValues[$stackPtr]['prev'] === $content
                && $this->oldTokenValues[$stackPtr]['loop'] === ($this->loops - 1)
            ) {
                if (PHP_CODESNIFFER_VERBOSITY > 1) {
                    $indent = "\t";
                    if (false === empty($this->changeset)) {
                        $indent .= "\t";
                    }

                    $loop = $this->oldTokenValues[$stackPtr]['loop'];

                    @ob_end_clean();
                    echo "{$indent}**** {$sniff}:{$line} has possible conflict with another sniff on loop {$loop}; caused by the following change ****" . PHP_EOL;
                    echo "{$indent}**** replaced token {$stackPtr} ({$type} on line {$tokenLine}) \"{$oldContent}\" => \"{$newContent}\" ****" . PHP_EOL;
                }

                if ($this->oldTokenValues[$stackPtr]['loop'] >= ($this->loops - 1)) {
                    $this->inConflict = true;
                    if (PHP_CODESNIFFER_VERBOSITY > 1) {
                        echo "{$indent}**** ignoring all changes until next loop ****" . PHP_EOL;
                    }
                }

                if (PHP_CODESNIFFER_VERBOSITY > 1) {
                    ob_start();
                }

                return false;
            }//end if

            $this->oldTokenValues[$stackPtr]['prev'] = $this->oldTokenValues[$stackPtr]['curr'];
            $this->oldTokenValues[$stackPtr]['curr'] = $content;
            $this->oldTokenValues[$stackPtr]['loop'] = $this->loops;
        }//end if

        $this->fixedTokens[$stackPtr] = $this->tokens[$stackPtr];
        $this->tokens[$stackPtr] = $content;
        ++$this->numFixes;

        if (PHP_CODESNIFFER_VERBOSITY > 1) {
            $indent = "\t";
            if (false === empty($this->changeset)) {
                $indent .= "\tA: ";
            }

            if (ob_get_level() > 0) {
                ob_end_clean();
            }

            echo "{$indent}{$sniff}:{$line} replaced token {$stackPtr} ({$type} on line {$tokenLine}) \"{$oldContent}\" => \"{$newContent}\"" . PHP_EOL;
            ob_start();
        }

        return true;
    }

    //end replaceToken()

    /**
     * Reverts the previous fix made to a token.
     *
     * @param int $stackPtr The position of the token in the token stack.
     *
     * @return bool If a change was reverted.
     */
    public function revertToken($stackPtr)
    {
        if (false === isset($this->fixedTokens[$stackPtr])) {
            return false;
        }

        if (PHP_CODESNIFFER_VERBOSITY > 1) {
            $bt = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
            if ('PHP_CodeSniffer\Fixer' === $bt[1]['class']) {
                $sniff = $bt[2]['class'];
                $line = $bt[1]['line'];
            } else {
                $sniff = $bt[1]['class'];
                $line = $bt[0]['line'];
            }

            $sniff = Util\Common::getSniffCode($sniff);

            $tokens = $this->currentFile->getTokens();
            $type = $tokens[$stackPtr]['type'];
            $tokenLine = $tokens[$stackPtr]['line'];
            $oldContent = Common::prepareForOutput($this->tokens[$stackPtr]);
            $newContent = Common::prepareForOutput($this->fixedTokens[$stackPtr]);
            if ('' === trim($this->tokens[$stackPtr]) && true === isset($tokens[($stackPtr + 1)])) {
                // Add some context for whitespace only changes.
                $append = Common::prepareForOutput($this->tokens[($stackPtr + 1)]);
                $oldContent .= $append;
                $newContent .= $append;
            }
        }//end if

        $this->tokens[$stackPtr] = $this->fixedTokens[$stackPtr];
        unset($this->fixedTokens[$stackPtr]);
        --$this->numFixes;

        if (PHP_CODESNIFFER_VERBOSITY > 1) {
            $indent = "\t";
            if (false === empty($this->changeset)) {
                $indent .= "\tR: ";
            }

            @ob_end_clean();
            echo "{$indent}{$sniff}:{$line} reverted token {$stackPtr} ({$type} on line {$tokenLine}) \"{$oldContent}\" => \"{$newContent}\"" . PHP_EOL;
            ob_start();
        }

        return true;
    }

    //end revertToken()

    /**
     * Replace the content of a token with a part of its current content.
     *
     * @param int $stackPtr The position of the token in the token stack.
     * @param int $start    The first character to keep.
     * @param int $length   The number of characters to keep. If NULL, the content of
     *                      the token from $start to the end of the content is kept.
     *
     * @return bool If the change was accepted.
     */
    public function substrToken($stackPtr, $start, $length = null)
    {
        $current = $this->getTokenContent($stackPtr);

        if (null === $length) {
            $newContent = substr($current, $start);
        } else {
            $newContent = substr($current, $start, $length);
        }

        return $this->replaceToken($stackPtr, $newContent);
    }

    //end substrToken()

    /**
     * Adds a newline to end of a token's content.
     *
     * @param int $stackPtr The position of the token in the token stack.
     *
     * @return bool If the change was accepted.
     */
    public function addNewline($stackPtr)
    {
        $current = $this->getTokenContent($stackPtr);

        return $this->replaceToken($stackPtr, $current . $this->currentFile->eolChar);
    }

    //end addNewline()

    /**
     * Adds a newline to the start of a token's content.
     *
     * @param int $stackPtr The position of the token in the token stack.
     *
     * @return bool If the change was accepted.
     */
    public function addNewlineBefore($stackPtr)
    {
        $current = $this->getTokenContent($stackPtr);

        return $this->replaceToken($stackPtr, $this->currentFile->eolChar . $current);
    }

    //end addNewlineBefore()

    /**
     * Adds content to the end of a token's current content.
     *
     * @param int    $stackPtr The position of the token in the token stack.
     * @param string $content  The content to add.
     *
     * @return bool If the change was accepted.
     */
    public function addContent($stackPtr, $content)
    {
        $current = $this->getTokenContent($stackPtr);

        return $this->replaceToken($stackPtr, $current . $content);
    }

    //end addContent()

    /**
     * Adds content to the start of a token's current content.
     *
     * @param int    $stackPtr The position of the token in the token stack.
     * @param string $content  The content to add.
     *
     * @return bool If the change was accepted.
     */
    public function addContentBefore($stackPtr, $content)
    {
        $current = $this->getTokenContent($stackPtr);

        return $this->replaceToken($stackPtr, $content . $current);
    }

    //end addContentBefore()

    /**
     * Adjust the indent of a code block.
     *
     * @param int $start  The position of the token in the token stack
     *                    to start adjusting the indent from.
     * @param int $end    The position of the token in the token stack
     *                    to end adjusting the indent.
     * @param int $change The number of spaces to adjust the indent by
     *                    (positive or negative).
     */
    public function changeCodeBlockIndent($start, $end, $change)
    {
        $tokens = $this->currentFile->getTokens();

        $baseIndent = '';
        if ($change > 0) {
            $baseIndent = str_repeat(' ', $change);
        }

        $useChangeset = false;
        if (false === $this->inChangeset) {
            $this->beginChangeset();
            $useChangeset = true;
        }

        for ($i = $start; $i <= $end; ++$i) {
            if (1 !== $tokens[$i]['column']
                || $tokens[($i + 1)]['line'] !== $tokens[$i]['line']
            ) {
                continue;
            }

            $length = 0;
            if (T_WHITESPACE === $tokens[$i]['code']
                || T_DOC_COMMENT_WHITESPACE === $tokens[$i]['code']
            ) {
                $length = $tokens[$i]['length'];

                $padding = ($length + $change);
                if ($padding > 0) {
                    $padding = str_repeat(' ', $padding);
                } else {
                    $padding = '';
                }

                $newContent = $padding . ltrim($tokens[$i]['content']);
            } else {
                $newContent = $baseIndent . $tokens[$i]['content'];
            }

            $this->replaceToken($i, $newContent);
        }//end for

        if (true === $useChangeset) {
            $this->endChangeset();
        }
    }

    //end changeCodeBlockIndent()
}//end class
